Do you always consider before dental implant placement the biological risk factors your patient may have?
These factors have a significant impact on the outcome of the surgery. Furhermore, they affect on the longevity of the dental implant placed. According to Dr Joseph Choukroun: following a failure of a bone graft or an implant placement, the hypothesis of a biological abnormality is rarely considered as a possible cause.
“When I see a yellow bone, I cancel the implant surgery!” – said Branemark in 1985 during an international meeting.
The search for a biological anomaly labeled as a risk factor before oral surgery is limited to diseases such as diabetes. However, it has been developed in recent years that cholesterol and vitamin D levels should be more systematically investigated before dental implant placement. Good cholesterol (high-density lipoprotein [HDL]) and bad cholesterol (low-density lipoprotein [LDL]) need to be included in this investigation because both could have a negative effect on bone growth and osseointegration (high LDL or low HDL).
Excess low-density lipoprotein cholesterol (dyslipidemia) is responsible for a slower bone metabolism or lower dental implant osseointegration.
LDL cholesterol and bone metabolism
Cholesterol is transported in the plasma predominantly as cholesteryl esters associated with lipoproteins. There are 2 types of lipoproteins: LDL (bad) and HDL (good).
In addition to cardiovascular diseases, there is evidence that high levels of cholesterol and triglycerides cause alterations in bone tissue. Krieger demonstrated an increase in the number of osteoclasts, the inhibition of osteoblastic activity, and a decreased bone remodeling in hyperlipidemic rats. According to Luegmayr et al, elevated levels of cholesterol may lead to an imbalance in the bone-remodeling process, a reduction of bone mass by increasing the activity, and a differentiation of osteoclasts. Furthermore, recent studies have pointed out possible links between periodontal infection and an increased risk for cardiovascular disease.
An increase of circulating levels of oxidized LDL induces alveolar bone loss and is associated with the severity of the local inflammatory response to bacteria as well as the susceptibility to periodontal disease in diabetic patients.
Indeed, the Demer group showed that oxidized LDL caused an inhibition of the alkaline phosphatase activity and also mineralization, which are markers of osteoblast differentiation. In addition, it has recently been shown that oxidized LDL also induces cell death by apoptosis of osteoblastic cells.
Hirasawa et al confirmed that atherogenic conditions (high LDL levels) caused the death of osteoblasts.
What is the role of HDL?
Various antioxidants carried by HDL may interrupt the cascade of events leading to the oxidation of LDL. Another important property of HDL is its ability to inhibit cell death induced by oxidized LDL. In particular, it has been reported that HDL inhibits the apoptosis of monocytic cells by inducing cholesterol efflux and thus preventing the accumulation of cholesterol caused by the presence of oxidized LDL. HDL should be considered as a bone cell protector.
The result of high LDL is a reduction of bone metabolism, inhibition of phosphatase alkaline, and an increase of the fat part in the bone. The result is a lower osseointegration and slower bone growth.
Case studies have shown higher failure rate of implants and bone grafting by patients with high LDL and low HDL.
Branemark’s statement in 1985 was only a clinical observation. But now we understand the reason. We have been focusing on the high cholesterol risk in bone grafts for more than 10 years, and now we can explain why we had more failures in these cases.
It is suggested examining vitamin D serum level (prescription: 25OH vitamin D = D2 + D3) and LDL Cholesterol (prescription: cholesterol total + LDL + HDL cholesterol) systematically in patients who are diabetic, allergic, with hypertension, and with previous difficulties of implants and/or bone grafting.
Reference: Dr Joseph Choukroun: Two neglected biologic risk factors in bone grafting and implantology: high low-density lipoprotein cholesterol and low serum vitamin D.
If you would like to know more about the biological background of predictable dental implant placement and longevity, furthermore if you wish to expand your knowledge on Platelet Rich Fibrin than look no further as Dr Choukroun is here to explain all.
🔸Dr Choukroun’s upcoming Platelet Rich Fibrin -PRF- course is an enlightenment on the biological and mechanical conditions for long term stability and success of bony and soft tissue management.
🔸All positive and negative factors which control angiogenesis, blood supply and bone metabolism will be presented.
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